Ga2O3 films were deposited onto Si(111)substrates with radio frequency(r.f.)magnetron sputtering system.They self-assembled into GaN films after reacted with ammonia.The lattice mismatch between substrates and epitaxy layer affects the films' quality.In order to optimize the films,thin SiC films as intermediate layers also deposited onto the substrate with magnetron sputtering.The samples intermediate were compared.The results indicate intermediate layer's positive effect to GaN films.